feat: Enhance take_screenshot for multi-monitor support

[onyedikachi-david]

Fixes #766 /claim #766

What kind of change does this PR introduce?

Feature

Summary

This PR introduces support for multi-monitor setups in the take_screenshot function. It includes the following changes:

• Implemented get_current_monitor to determine the monitor where the cursor is currently located.
• Modified take_screenshot to use get_current_monitor for capturing the correct monitor.
• Added comprehensive tests for take_screenshot with multiple monitors.
• Mocked get_current_monitor and mss.mss in tests to simulate multiple monitor configurations.
• Ensured take_screenshot correctly handles multiple monitors and returns the expected screenshot.

Checklist

• [x] My code follows the style guidelines of OpenAdapt
• [x] I have performed a self-review of my code
• [x] If applicable, I have added tests to prove my fix is functional/effective
• [x] I have linted my code locally prior to submission
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation (e.g. README.md, requirements.txt)
• [x] New and existing unit tests pass locally with my changes

How can your code be run and tested?

To run and test the code:

1. Ensure you have the necessary dependencies installed.
2. Run the test suite using pytest:

pytest tests/openadapt/test_monitors.py

3. Verify that all tests pass, including the new tests for multi-monitor support.

Other information

No additional context needed.